After years of responding to e-mails on this topic, Bruxy Cavey preached two sermons specifically on Zeitgeist. You can access them by subscribing to the MeetingHouse Audiocast, or the MeetingHouse VideoCast. The sermons are in the series "Duped," and are the two sermons entitled "Did Jesus Exist" and "Jesus - Christ or Copycat?". These sermons are also available from the MeetingHouse homepage. (Note: if you watch the video, be sure to also get the audio version, which has the so-called "drive-home" section. This is where Bruxy talks about everything he didn't have time to say in the sermon. In this case, it is a lot of very interesting material!)